The present invention relates generally to a biochemical assay for use in medical diagnosis and prognosis, and more specifically to an immunoassay for the diagnosis of autoimmune sensorineural hearing loss.
Autoimmune sensorineural hearing loss (ASNHL) is a disease characterized by progressive unilateral or bilateral deafness that, in its incipient stages, may fluctuate or become sudden and profound. Often disturbances of balance accompany the deafness. The pathogenesis of ASNHL and vestibular dysfunction is not well understood, but is presumed to include vasculitis of vessels supplying the inner ear, autoantibodies directed against inner ear antigenic epitopes or cross-reacting antibodies.
There are a number of disorders associated with hearing loss that have symptoms similar to autoimmune sensorineural hearing loss, thus making recognition of ASNHL difficult. The other disorders resulting in deafness include Meniere's disease, viral labyrinthitis, perilymph fistula, otosyphilis, and congenital or hereditary deafness. The determination of a specific etiology of the disease is of paramount importance with regard to determining appropriate therapeutic regimen.
Currently, no reliable test for autoimmune sensorineural hearing loss exists, although attempts have been made to develop one. Lymphocyte blastogenesis transformation assays against inner ear tissue and migration inhibition assays have been used, but both have low sensitivity. Immunofluorescence microscopy on animal or human temporal bones have also been used, but this procedure is technically difficult to perform because decalcification for sectioning alters antigenicity of the target tissue.
Thus, a need exists for a reliable test for autoimmune sensorineural hearing loss. Preferably, the test would be easy to perform and would be useful for predicting and monitoring a patient's response to immunosuppressive therapy. The present invention satisfies this need and provides related advantages as well.